Multi-outlet power strips are designed to provide power access to a plurality of electrical plugs. Power strip characteristics, such as size, design, shape, mounting configuration, etc. can vary widely. For example, a small, portable power strip can have a relatively short housing designed to accommodate a small number of plugs via plug apertures closely spaced together. A cord or cable connected to the housing terminates in a plug that can be inserted into an existing wall or floor outlet to expand the number of devices that the pre-existing outlet can serve. The portable power strip can be removed when no longer needed, and reused in an alternate location. Alternatively, a multi-outlet power strip can be installed in a fixed location at a consumer residence, public facility, commercial building, or other site, for example in a floor, at a work station, under a cabinet, etc. Typically, an installed power strip offers several advantages over a portable power strip, such as, but not limited to: having a housing configured to receive and accommodate wiring directly from a junction box, enabling a junction box to serve a plurality of appliances and devices in an aesthetically pleasing manner, obviating the need for an unsightly power cord to dangle from a wall or stretch across a floor to connect with a wall or surface outlet, and reducing the number of openings that must be cut in a wall or floor to deliver electricity to multiple devices simultaneously. At the same time, however, installation of power strips can be time-consuming, with errors or faults in the installation process possibly degrading power strip performance or even rendering a power strip inoperable. Manufacturers who attempt to improve performance, convenience, appearance or ease of installation, are constrained by government and industry standards that regulate power strip design and use. Design modifications and features that have been implemented to improve power strip performance and appearance often fail to have their intended effect, or fail to address all current deficiencies. As a result, presently known power strips continue to suffer one or more disadvantages.
For example, the Underwriter Laboratory (UL) 111 standard requires that a metal enclosure of a power strip be properly connected to a ground wire of incoming supply wiring used to connect outlets or receptacles of the power strip to a power source, such as an electric junction box behind a wall or floor of a building. Existing power strips, such as the Wiremold AL2000 System require an installer to insert a ground clamp in a back channel of the power strip, then loop a ground supply wire around the ground clamp's stud. Having looped the ground supply wire, the installer can then connect the supply ground wire to a ground wire that runs through the power strip receptacles. As an alternative to looping the supply wire around the ground clamp stud, an installer can attach a pigtail wire to the stud, then splice the ground supply wire with the pigtail. The installer may then connect the spliced supply wire with the ground wire running through the several receptacles contained within the front channel. The supply wiring is then folded back into the channel area. The front channel can then be coupled to the back channel, typically through a friction fit in which the two channel portions are snapped together. The front channel is connected to the ground path through its interface with the back channel.
While adequate for its intended purpose, the apparatus and method discussed above have several shortcomings and disadvantages. One disadvantage is the amount of time it takes for an operator to install a power strip. An installer must take time to insert and secure a ground clamp into a back channel of the power strip, insert and pull supply wiring into the back channel, connect the ground supply wire to the clamp, then connect the supply wire to the wiring of a receptacle harness. The back channel offers limited space for pulling the supply wires through, connecting them with receptacle wiring, and storing the supply wiring after the appropriate connections are made. The more difficult the pulling, connecting and storing process is, the longer the installation time will be, and the more costly installation of the apparatus becomes. Efforts to shorten the wiring that is folded and stored within the assembled channel must be exercised with care, as any attempt to shorten the wire necessarily shortens the distance by which the two channel portions can be separated during installation or maintenance. When the wire length becomes too short, which can happen at the ends of a channel, there is no longer enough wire or space between the channel portions to connect the supply wiring with the receptacle wiring. In this situation, an operator typically installs an end supply box to provide additional space to for splicing wires together and storing the folded back wiring. The end feed box can spoil the appearance of the installed outlet assembly, as well as add time and cost to the installation process.
To obviate the need for an installer to physically connect a feed ground wire to a ground clamp, the PlugMold 2000 steel series provides an alternative ground connection. A metallic projection is disposed at the back of each receptacle of a receptacle harness. When the front and back channels are snapped together, the projections are designed to contact the steel enclosure of the back channel to provide a ground connection between the two channels. While possibly conserving some time and space, this apparatus and method have the disadvantage that the projections that extend across and between the two channels prevent wiring from being passed underneath any of the receptacles. In addition, if the front and back channels are not pushed together tightly and completely, the ground projections will not have sufficient contact with the back channel to provide the necessary ground connection.
A further drawback of prior art channel assemblies is that they generally require an installer to hold a back channel in place while securing the back channel to a mounting surface. Underwriter Laboratories 111 Standard 4.6.C. limits mounting holes on a base or base fitting surface to a maximum diameter of 7.1 mm, and limits slotted openings to dimensions no greater than 15.9 mm in one direction and no greater than 3.2 mm in the other dimension. These restrictions prevent inclusion of a keyhole opening on a back channel that could be slipped over a screw in a mounting bracket to hold the back channel in place while an installer inserts and tightens mounting screws.